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Mac 275 questions........

After some months of up's and down's with my ASL Hurricanes (just seemed to never stay operational for longer then 2-3 months) I have decided o retire them and get the McIntosh MC 275 (2 amps).

I have some questions for you all and appreciate any input you may have (especially form Mac owners) but opened to all.
My speakers are Infinity RS 1-B's and I will be using the amps to drive the top end of the system (EMIM's and EMIT's). I have a Perreaux 3150B for the bass columns. The Infinities are rated at 4 ohms.
I plan to listen to one amp on top ( I will get one amp in a week) and then when I get the 2nd amp ( a week later) run both in mono.
What will I hear with each application? First with one and then with both? Also can any of you let me know if any of you compared the Mac 275 (in mono) 150 watts with the Hurricanes 200 wpc? The Hurricanes were great but I just could not live with them being up and down so many times.

Thanks to all for your input.

RWD (Rick)
rwd
gregpen
9 posts
 
If one is looking towards the rear of the 2275 from the front, Which pair of 12ax7a is used for the phono, the pair on the left or the right pair?
nsgarch's avatar
nsgarch
2,524 posts
 
Greg, the fastest way to answer that question would be to call McIntosh. While you're at it, order a service manual/schematic -- that's what I did.

You can also find out by 'naming' the phono input something else (on the menu screen) if you do that, the phono tubes won't light up when you turn the amp on -- at least that's the way their preamps work ;-) (It's a way of saving tubes and reducing heat if you don't have a turntable.)
ontjesr
157 posts
 
Hey Gregpen, I have a 2275 and the tube slots/function follows. The best swap is what you have already performed, the 12AT7's in slots V1R & V1L. These peform the function of "preout" tubes and are VERY IMPORTANT. Slots V4 & V5 are for phono and V6 & V7 are for tone controls (bass/treble). If you aren't using a TT, then any ole 12AX7 is fine. Additionally, I have switched my tone controls to off on the front display, so, I have plain ole 12AX7's in those slots (V6 & V7) as well.
rgurney
279 posts
 
Ontjesr - Thanks for that info. From what you say, if one does not use the phono section and wants to get the best sound, one should use the best NOS 12AT7's, and use some plain new production 12AX7's.
Any suggestions on NOS 12AT7's from your experience?
rwd OP
695 posts
 
I wanted to respond to everyone since I was the original author of this thread. I have been listening to one Mac 275 for 3 weeks now. I am getting the other 275 installed this weekend. I hope to report to all of you the outcome.
There certainly is a difference between the Mac275 (one) and the ASL Hurricanes. Some pluses and some minus.
Hold tight and let me do some listening Saturday and Sunday (before the game) and I will report to you all.

Rick (RWD)
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